The present invention relates to an electronic device test holding device, an electronic device test apparatus, and an electronic device test method suitable for high temperature testing of an IC chip or other electronic device.
In the process of manufacture of a semiconductor device, a test apparatus is required for testing the finally produced IC chip or other electronic device. Such a test apparatus conducts this test while pressing the terminals of the IC chip under test against connection terminals of a test socket.
An electronic device has to be guaranteed to operate even under harsh environments, so is sometimes tested under certain temperatures (for example, 125xc2x0 C. or so) higher than ordinary temperature. In the case of such a high temperature test, the electronic device is heated to that certain temperature before connecting the electronic device to the connection terminals of the test socket. Further, when conveying the electronic device to the test socket after heating, to prevent the electronic device from being cooled and the temperature from falling, the electronic device holding device for holding and conveying the electronic device is provided with a heater for preventing a drop in temperature of the electronic device.
An IC chip or other electronic device, however, is small in heat capacity, so when conveying the electronic device, pressing it against the connection terminals of the test socket, and starting the test, heat is robbed from the electronic device by the connection terminals and the temperature of the electronic device easily falls. That is, the temperature of the electronic device, which is held at a certain temperature at so much effort by the heater of the electronic device holding device, falls along with the start of the test and therefore the electronic device can no longer be tested at the predetermined set temperature. This causes a remarkable drop in the reliability of the test.
To prevent this inconvenience, it may also be considered to provide a heater at the test socket side to prevent a drop in temperature of the electronic device.
With this technique, however, since each time the electronic device to be tested changes, the test socket also changes, it is necessary to design the heater, which is to be attached for each test socket, for each individual socket. The design man-hours for this increases and the manufacturing cost of the test apparatus rises. Further, since a heater is required for each type of socket, the running cost of the test apparatus also increases.
The present invention has been made in consideration of this actual situation and has as its object the provision of an electronic device test holding device, electronic device test apparatus, and electronic device test method able to maintain an electronic device to be tested at a predetermined high temperature state and perform a high temperature test well without causing an increase in the manufacturing cost or running cost of the test apparatus.
To achieve the above object, an electronic device test holding device according to the present invention comprises:
a holding head for detachably holding and conveying an electronic device for connecting the electronic device with connection terminals for testing,
a heating means attached to said holding head and able to heat said electronic device in accordance with need,
a cooling means attached to said holding head and able to cool said electronic device in accordance with need, and
a controlling means for controlling said heating means and said cooling means so as to heat said electronic device by said heating means and to cool said electronic device by said cooling means while conveying said electronic device by said holding head and so as to heat said electronic device by said heating means and to stop or weaken the cooling by said cooling means when pressing said electronic device to said connection terminals by said holding head.
Further, an electronic device test apparatus according to the present invention comprises:
connection terminals for testing,
a holding head for detachably holding and conveying an electronic device for connecting the electronic device with connection terminals for testing,
a heating means attached to said holding head and able to heat said electronic device in accordance with need,
a cooling means attached to said holding head and able to cool said electronic device in accordance with need,
a movement mechanism for making said holding head move in a horizontal direction and/or a vertical direction, and
a controlling means for controlling said heating means and said cooling means so as to heat said electronic device by said heating means and to cool said electronic device by said cooling means while conveying said electronic device with said holding head drived by said movement mechanism and so as to heat said electronic device by said heating means and to stop or weaken the cooling by said cooling means when pressing said electronic device to said connection terminals by said holding head.
Preferably, said controlling means controls said cooling means so as to rob from said electronic device during the conveyance of said electronic device an amount of heat corresponding to the amount of heat which escapes from said electronic device to said connection terminals when said electronic device contacts said connection terminals.
Preferably, said cooling means is a cooling air discharge nozzle. Another cooling means is an electronic cooling means using a Peltier device etc. Further, it may also be cooling by contact with a metal having a large heat mass.
Preferably, said cooling air discharge nozzle is formed integrally with a discharge opening of a cooling air passage formed inside said holding head. The cooling air discharge nozzle however may also be the front end opening of a cooling tube attached to the holding head.
Preferably, said holding head is provided with a suction holding nozzle for detachably holding an electronic device by suction. In this case, preferably said cooling means is a cooling air discharge nozzle. Said cooling air discharge nozzle is formed around said suction holding nozzle.
An electronic device test method according to the present invention is characterized by:
heating an electronic device and cooling said electronic device while conveying said electronic device,
heating said electronic device and stopping or weakening the cooling when pressing said electronic device against connection terminals for a test, and
controlling the temperature of the electronic device during conveyance so as to become approximately equal to the temperature of the electronic device during the test.
Preferably, said cooling means is controled so as to rob from said electronic device during the conveyance of said electronic device an amount of heat corresponding to the amount of heat which escapes from said electronic device to said connection terminals when said electronic device contacts said connection terminals.
Preferably, said electronic device is cooled while testing said electronic device in the same way or slightly less cooling way as during conveyance of said electronic device after the temperature of said test connection terminals approaches the temperature of said electronic device.
The electronic device test apparatus and test method having the electronic device test holding device according to the present invention heat and cool the electronic device while conveying the electronic device and heat the electronic device and stop or weaken the cooling of the electronic device when pressing the electronic device against connection terminals for a test.
That is, they heat the electronic device to a temperature higher than the set temperature of the test and cool the electronic device to close to the set temperature of the test during conveyance of the electronic device. Further, they stop or weaken only the cooling of the electronic device while pressing the electronic device against the connection terminals for a test. The electronic device from the electronic device holding device continues to be heated. If pressing an electronic device against connection terminals, the heat of the electronic device is robbed by conductance from there and the temperature of the electronic device falls. When pressing an electronic device against connection terminals, however, the cooling of the electronic device is stopped or weakened almost simultaneously, so the escape of heat by conduction to the connection terminals is canceled by the stopping or weakening of the cooling of the electronic device and the temperature of the electronic device is maintained at the set temperature of the test.
Therefore, in the present invention, it becomes possible to maintain the temperature of the electronic device during the test at a predetermined set temperature without attaching a heater to the test socket side where the connection terminals are provided and possible to conduct a test accurately with a high reliability.
Note that if continuously testing electronic devices, the connection terminals of the test socket also gradually will rise in temperature and the movement of heat due to conductance from the electronic devices to the connection terminals becomes smaller. In such a case, it is sufficient not to completely stop the cooling by the cooling means of the electronic device holding device, but to continue cooling by a cooling efficiency smaller than during conveyance of the electronic devices.